1. Field of the Invention
This invention relates to a lockable fastener.
2. Description of Prior Art
Traditional threaded fastening devices for attaching objects in a vibration prone environment are subject to undesirable loosening eventually precipitated by such vibration or other undesirable external forces. In an attempt to alleviate this loosening problem in a threaded fastening system, various lockable nut and bolt devices have been employed in which the rotational locking mechanism has been integral with or closely adjacent to the nut or the bolt head and resiliently impressed thereon. However, one or more of the following undesirable characteristics are inherent in such devices.
One such problem has been that a special tool is often required to disengage the locking means prior to loosening of the threaded connection with a wrench. Additionally, the components of such devices are usually separate, requiring some degree of assembly prior to each fastening operation and allowing the components to fall away from the fastened objects upon loosening of the device, thus being lost or causing damage to adjacent mechanisms. Another problem encountered with traditional lockable threaded fastening devices is that the rotational locking characteristics of some such devices are dependent upon the configuration of a portion of one of the objects to be fastened. The result is that a given device of this type is unsuitable for use on an object having a different configuration. A further problem encountered is that some devices do not provide for loosening of the threaded connection, after tightening, without damage to the workpiece and/or some of the fastening device components.